Vertebral Column Terms

Cervical Vertebrae

Contains 7 bones?

Thoracic Vertabrae

Contains 12 bones?

Lumbar Vertebrae

Contains 5 bones?

Sacrum

5 fused bones (segments)

Vertebrae

Contains 33 bones total?

Coccyx

4 incomplete bones (segments)

Lordotic/Convex anteriorly

The cervical curvature is ______

Kyphotic/Concave anteriorly

The thoracic curvature is _____

Lordotic/Convex anteriorly

The lumbar curvature is _____

Kyphotic/Concave anteriorly

The pelvic curvature is _____

Vertebra (structure of a typical vertebra)

• A bone of the vertebral column

• Has a body, an arch, 7 processes, and a vertebral foramen

Body of vertebrae (structure of a typical vertebra)

The solid anterior part shaped like a cylinder, with the posterior surface flattened

The arch of vertebrae (structure of a typical vertebra)

• The curved posterior part enclosing an opening

• Has 2 pedicles and 2 laminae that, together with the posterior surface of the body, form a vertebral foramen

Pedicles (structure of a typical vertebra)

2 short processes that extend posteriorly, one from each lateral margin of the dorsal surface of a vertebral body

Laminae (structure of a typical vertebra)

• 2 flattened plates of bone, one projecting back from each pedicle

• They unite posteriorly in the midline to form the spinous process and to complete the vertebral arch

Vertebral foramen (structure of a typical vertebra)

An opening formed by the vertebral arch with its pedicles and laminae and the posterior surface of the vertebral body

Vertebral canal (structure of a typical vertebra)

• A tubular passage extending from the foramen magnum of the skull to the lower sacrum

• Formed by the vertebral foramen of the vertebrae

Vertebral foramen/canal (structure of a typical vertebra)

The spinal cord extends down through this canal

Vertebral notch (structure of a typical vertebra)

• Formed by either the upper or lower surface of a pedicle

• There is a superior and inferior notch on each side at each level, posterior to the vertebral body

Intervertebral foramen (foramina) (structure of a typical vertebra)

• An opening on each side of the arch, formed by an inferior notch of one vertebra and the superior notch of the vertebra below

• A spinal nerve leaves the spinal cord through each of these openings

Transverse processes (2) R and L

Extend laterally from the junction of a pedicle with a lamina on each side

Superior articular processes (2) R and L

Extend up towards the head from the junction of each pedicle and lamina

Inferior articular processes (2) R and L

• Project caudally (downwards) from the junction of each pedicle and lamina

Inferior articular processes (2) R and L

• The ______ processes of one vertebrae form. joints with the superior articular processes of the vertebra below

• Lies posterior to the corresponding superior processes

Single spinous process (1)

Extends posteriorly from the dorsal margin of each vertebral arch, at the junction of the R and L laminae

Larger

Vertebrae become progressively ____ from the cervical to the lumbar divisions

Cervical Vertebra

Small with spinous processes that are usually forked/bifid/doubled

Cervical Vertebrae

There is an opening in each of the transverse processes, a foramen transversarium/transverse foramen, through which the vertebral artery passes to reach the skull

Atlas - C1

Has no body and no spinous process; instead, it has 2 lateral masses of bone and 2 arches (these together surround the vertebral foramen)

Lateral masses of C1 Atlas

Solid masses of bone that lie on either side of the vertebral foramen and support the articular facets - they are joined anteriorly by an anterior bony arch, and posteriorly by a posterior arch of bone

Anterior arch of C1 Atlas

Forms the front wall of the foramen by uniting the 2 lateral masses here

Posterior arch of C1 Atlas

A curved structure that joins the posterior parts of the lateral masses together, completing a bony ring

Vertebral foramen of C1 Atlas

______ is large and is formed in front by the anterior arch, laterally by the lateral masses, and behind by the posterior arch. A transverse ligament passes across from one lateral mass to the other, dividing the foramen into 2 parts. The anterior part is occupied by the dens (odontoid process) of the 2nd vertebrae, while the posterior part contains the spinal cord

Superior and Inferior articular processes of C1 Atlas

Located on the superior and inferior surfaces of each lateral mass.

Superior articular process of C1/Atlas

The _____ articulates with a condyle of the occipital bone on the same side.

Inferior articular process of C1/Atlas

Articulate with the superior articular processes of the 2nd cervical vertebra below

Facet on the anterior arch of C1/Atlas

Articulates with the odontoid process on C2 to form the medial atlanto-axial joint

Axis/ C2

Has a tooth-shaped process extending upwards from its body. This dens/odontoid process fits into the anterior arch of the atlas above. It forms a pivot joint with this arch, allowing rotation of the head and atlas upon the axis

Vertebra Prominens/C7

• Has a larger and longer spinous process than the other cervical vertebra

• It is readily palpable at the base of the neck posteriorly

Thoracic vertebrae

Larger than cervical vertebrae

Thoracic vertebrae

Spinous processes are directed almost vertically caudally (towards the tail end of the body)

Costal facet for the tubercle of the rib (thoracic vertebrae)

This round pit lies on the anterior surface of a transverse process of a thoracic vertebrae. It forms a joint with a tubercle of a rib

Demi-Facet/Facet for the head of the rib (thoracic vertebrae)

Lies on the lateral surface of a thoracic vertebra close to its posterior margin, to articulate with the head of a rib

Lumbar Vertebrae

Larger than the thoracic vertebrae and become progressively larger towards the sacrum

Lumbar Vertebrae

Spinous processes are directed almost horizontally and posteriorly

Lumbar Vertebrae

Their transverse processes have no foramina and no facet for ribs

Sacrum

• Made up of 5 vertebrae that have become united to form a single bone

• Forms the posterior part of the pelvic girdle, between hip bones

Sacral segments

In the fetus and young child, the ______ are separated by cartilages

Body (central part) of Sacrum

The large curved area that is formed from the fused bodies of the 5 sacral segments

The lateral masses (lateral parts) of sacrum

Lie one on either side of the fused bodies, lateral to the sacral foramina. Each lateral part is made up of the fused transverse processes and costal elements of the 5 fused vertebrae

The Ala of Sacrum

Wing-like upper part of each lateral mass, view from above

Sacral Promontory of the sacrum

The prominent anterior margin of the upper sacral segment

The superior articular processes of Sacrum

Extend up from the posterolateral margins of the sacrum on each side. Their articular surfaces are directed posteriorly and form joints with the inferior articular processes of L5

The base of sacrum

Articulates with body of L5 - 1st sacral segment

The apex of sacrum

The small inferior end which articulates with the first segment of the coccyx

The sacral cornu

Two small bony projections that extend caudally from the lower sacrum posteriorly, one on each side of the sacral hiatus. They form joints with similar cornea of the coccyx.

Sacroiliac joints

Two auricular facets; located one on each lateral surface of the sacrum. These rough areas join the auricular surfaces of the iliac ones to form ___.

Coccyx

• Usually formed by 4 (sometimes 3 or 5) incompletely developed vertebrae

• The segments often remain as separate bones

Coccyx

The upper end of the ____ forms a joint with the apex of the sacrum

The Cornua of coccyx

Are 2 small bony processes that extend up from the posterior surface of the coccyx to meet similar cornua of the sacrum

Intervertebral joints

• Located between the flat articular surfaces of bodies of adjacent vertebrae from the 2nd cervical vertebrae (C2) to and including the lumbosacral joint between L5 and sacrum

• From C2-L5/S1

• Most movement occurs in cervical and lumbar divisions, with minimal movement in thoracic

Interarticular joints

• R and L

• Located between articular processes of the adjacent vertebrae on each side

• Formed by inferior articular processes of one vertebra articulating with superior articular process of the vertebrae below on the same side of the body

Atlantooccipital Joints

• 2, R and L

• Located between the atlas and occipital bone

• Formed by an occipital condyle of the occipital bone articulating with the superior articular surface on the lateral mass of the atlas on the same side

Atlantoaxial joints

• 1 median and 2 lateral (R & L)

• Located between the atlas and axis

Median Atlantoaxial joint

Located between the dens of the axis and a ring formed by the anterior arch of the atlas

Lateral Atlantoaxial joint

• 2, R and L

• Located between the inferior articular surface of the lateral mass of the atlas and the superior articular process of the axis on each side

Lumbosacral joints

• A single joint

• Located between L5 and the upper end of the sacrum

Lumbosacral joints

• Formed by the inferior articular process of L5 and the superior articular process of the sacrum

• A cartilaginous joint

Sacrococcygeal joints

• Located between sacrum and coccyx

• Formed by distal end of sacrum forming a joint with the first segment of the coccyx

Intercoccygeal joints

Between segments of the coccyx, segments unite later in life